Electronic conductance of a lengthy zigzag honeycomb nanotube including some surface-adsorbed molecules

The effect of the adsorption of environmental polyatomic molecules on the electronic transport properties of a lengthy zigzag honeycomb nanotube is investigated using the Green's function formalism within the tight-binding approach. We follow the theoretical approach in our previous paper, (Nadri et al 2019 Chin. Phys. B 28 017202), which is done for a lengthy armchair honeycomb nanoribbon. Three types of adsorbed molecules are considered: di-, tri- and tetra-atomic ones which are located at a small part in the middle of the nanotube. The results show that in the presence of adsorbed molecules, the original band gap of the nanotube becomes wider and at some molecular concentrations the system converts to a n- or p-type semiconductor. In some molecular concentrations and configurations, a new energy gap is opened that can produce new physical aspects in nanotubes.